[Limits of M-mode echocardiography in the diagnosis of cardiac tamponade].

The Authors examined the M-mode echocardiographic recordings concerning 15 patients with pericardial effusion; 2 of them showed clinical findings of cardiac tamponade. Some echocardiographic signs, related in literature as typical of cardiac tamponade, were analyzed: mitral E-F slope less than 50 mm/sec., right ventricular end-diastolic dimension at end expiration greater than 10 mm., reciprocal respiratory variations in right and left ventricular dimensions, notch on the right ventricular epicardial echo and/or interventricular septum during early systole. None of these signs was determinant in order to identify the patients with cardiac tamponade. Nevertheless one patient without cardiac tamponade showed all echocardiographic signs. The Authors believe that the diagnosis of cardiac tamponade remains eminently clinical; the utility of echocardiography consists in showing pericardial effusion.